filed a PR http://www.freebsd.org/cgi/query-pr.cgi?pr=154091
On Mon, Jan 17, 2011 at 6:43 AM, Adrian Chadd <adr...@freebsd.org> wrote:
> Hi,
>
> Please file a PR about this and the output of "show registers".
>
> I bet that the ip pointer isn't aligned at that point in the code.
> Whatever is passing the packet to the IP layer should be re-aligning
> things beforehand.
> (eg, look at what the ethernet ipfw hook code does - if the ether type
> is ipv4/ipv6, it actually realigns the packets before passing it back
> up the stack.)
>
>
>
> Adrian
>
> On 13 January 2011 16:25, Monthadar Al Jaberi <montha...@gmail.com> wrote:
>> sorry but I have not worked with this for a while now, After some
>> thoughts I dont think using netgraph will do me any good, because
>> traffic can still flow through the antennas of the cards.
>>
>> If you think it would still be useful to see more ddb prompt for other
>> scenarios I am happy to try and supply that, but I won't have some
>> free time until late tomorrow :)
>>
>> thnx again!
>>
>> On Thu, Jan 13, 2011 at 7:53 AM, Adrian Chadd <adr...@freebsd.org> wrote:
>>> I've encountered this before.
>>>
>>> The mbuf's there aren't always aligned at this point.
>>>
>>>
>>>
>>> Adrian
>>>
>>> On 13 January 2011 14:17, Jayachandran C. <c.jayachand...@gmail.com> wrote:
>>>> On Thu, Jan 13, 2011 at 11:08 AM, Adrian Chadd <adr...@freebsd.org> wrote:
>>>>> Find out what the address is that's causing the problem. There's
>>>>> plenty of places where unaligned mbuf's exist in the IP code and
>>>>> aren't correctly realigned before being touched.
>>>>>
>>>>> MIPS people - is "address error" an alignment problem?
>>>>
>>>> Address error can be an alignment problem (or some other cases like
>>>> accessing kernel address from userspace).
>>>>
>>>> But looking at the crash, it certainly seems like in ip_input, the line
>>>> 435 if (ip->ip_v != IPVERSION) {
>>>>
>>>> got a bad address for the ip pointer.
>>>>
>>>> The output of 'show registers' at the ddb prompt would be useful to
>>>> debug further.
>>>>
>>>>
>>>>> On 30 December 2010 21:47, Monthadar Al Jaberi <montha...@gmail.com>
>>>>> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> I have an idea in my head and would like to know if it is possible.
>>>>>>
>>>>>> I want to simulate and test the net80211 mesh code in FreeBSD Current.
>>>>>> I have an RSPRO board with 3 atheros cards.
>>>>>>
>>>>>> My basic idea is to run three jails each having its own network
>>>>>> stack, and redirect all data packets coming out/in of the wlan driver
>>>>>> to a Server running a home brew application that simulates the medium.
>>>>>> That would be great, right? Realtime unchanged code to test, running
>>>>>> different application in their own jails.
>>>>>>
>>>>>> So first I started to test netgraph with a simple test case, I want to
>>>>>> receive all packets from one wireless card and see the data in
>>>>>> wireshark or tcpdump...
>>>>>>
>>>>>> This is my netgraph code:
>>>>>> mkpeer wlan0: hub lower hook0
>>>>>> name wlan0:lower hub
>>>>>> connect hub: wlan0: hook1 upper
>>>>>> connect hub: arge0: hook2 lower
>>>>>>
>>>>>>
>>>>>> So if I understood man ng_ether correct, this should capture
>>>>>> everything from wlan and redirect to ethernet cable.
>>>>>>
>>>>>> But I get a panic after a couple of seconds:
>>>>>> Trap cause = 4 (address error (load or I-fetch) - kernel mode)
>>>>>> [ thread pid 11 tid 100037 ]
>>>>>> Stopped at ip_input+0xd8: lw v0,0(s0)
>>>>>>
>>>>>> I suspect that data flows to all hooks of the hub, and that is a bad
>>>>>> thing right? Need to create a special hub node to filter data? Or
>>>>>> maybe use two ethernet cables for out resp. in?
>>>>>>
>>>>>> Is it even possible to do what I want? Or am I thinking wrong? And is
>>>>>> there a simpler way?
>>>>>>
>>>>>> What I want is to test mesh code in a bunch of FreeBSD systems without
>>>>>> moving the hardware, one could just stack RSPROs and connected them a
>>>>>> big switch and a PC.
>>>>>> Hope was I clear in my thoughts.
>>>>>>
>>>>>> Best regards,
>>>>>> --
>>>>>> //Monthadar Al Jaberi
>>>>
>>>> JC.
>>>>
>>>
>>
>>
>>
>> --
>> //Monthadar Al Jaberi
>>
>
--
//Monthadar Al Jaberi
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